Apparatus for and method of enameling ware



Aug. 18. 1925 v 1,549,830

. C. A. HAHN APPARATUS FOR AND METHOD OF'ENAMELING WARE Filed Aug. 6, 1923 4 Sheets-Sheet 1 C. A. HAHN APPARATUS FOR AND METHOD OF ENAMELING WARE 7 Filed Aug '6, 1925 4 Sheets-Sheet 2 i I Y/JVVZ'IVTOP 44 1 14.179911 93M 6 1Q Aug. 18, 1925. 1,549,830

- c. A. HAHN APPARATUS FOR AND METHOD OF ENAMELING WARE Filed Aug. 6, 1923 4 Sheets-Sheet 3 4 /8 Aug. 18, 1925.

c. A. HAHN APPARATUS FOR AND METHOD OF ENAMELING WQRE Filed Aug. 6, 1 923 4 Sheets-Sheet 1 Patented Aug. 18, 1925.

can; A. HAHN, OF-ST.- Lou s; iss/0on1.

APPARATUS FOR AND METHOD OF EINANIH-LIZNTGr VVARJE.v

Application filed. August 6, 1923.; Serial No. 655,89}.

7 '0 all whom it may concern B it kn wr l mt I, CA L H N a t zen ofthe United States, and resident of the city ofSt. Louisand State of Missouri, have invented certain new and use ful Improvements in Apparatus for and Methods of EnamelingLVVare, of which the following is a specification containing a full, clear, and exact dcscription, reference being had to the mpanyin raw gs min a p there f.

My invention relates to improvements in airapparati stor and methodof @na eung re nd as i 12 s p m ry O ject at anparatus which'canbe readily heated and which avilllretajn or store up a great amount of heat and in which any foul gasesdue to combustion can: be readily; driven away from A still further object is to construct an enan'ieling furnace which isregenerative and in which a single valve controls the admission of air and fuel'for heating-purposes and the admission of air for scavenging.

In the drawings Big, 1 is a front elevationof my device with parts broken away;

Fig. 2 is a rear elevation of the same;

Fig. dis a vertical longitudinal section talccn enthe line 33 of Fig. 4;

Pin: is a vertical cross section taken on the line 4+4: of Fig, 3

Fig. 5 is a horizontal section taken on the line, 5 5 of Fig. 4:;

Fig. (.5V is a front plan view of the valve housing with thecover removed showing the valve plate, in position;

Fig. 7 is a horizontal section takencon the line 7-;7 of Fig, 6 with the cover in,

position;

F g, 8 3a onti tion of the al e housing showingithe cam used for operating etoilv vei' F 9 slran enlarged top Pla View. o the door with parts-broken awa and iii section showing the sali aattached to affia g mentor the furnacei A i i Fig ltl is a fraginental vertical cross seoa i the eer. Show ng he a epartly raised; i i

Fig. ll is. a verticalsefiition taken on the line 1l.11 ofl?ig. 0 showing the door slide resting on thestop i i Fig; 12;is anfeiilargedfragmfilltal iew illustrating the manner of securing the links to the door,

In constructing my apparatus l'employ a front wall 13, a rear wall lit a ndside walls 1Q. walls forming 'preferably,a rectangle. Spaced apart; from theside walls lijvare wallsjlfi whichare connected to; gether by means of an arch',17; )The space between thewa lls l5 "and l6 isfilled with heat insulating nateria1'18, such as asbestos fiber or any other commercial heating insu later. This insulating material is, also placed over thelarch, after which the space 19 may be filled in with clay or other ma terial such as sand and the like. This securely holds the insulating material in place and also further prevents radiation of heat. The walls 16 and arch l7form a chamber in the lower portion of which are arranged v vertical'walls 20 which divide that portion into a plurality of longitudinally extending passage ways 21. These passage ways in turnconnect with passage ways 22 formed through the rear wall lt and which open into; the regenerating chamber 23. This chamber is provided with a flue 24 which connects with a chimney 25. The flue'2l' is provided'with a damper 26 bymearis of which the passage of gases throughpthe' chimneycan be regulated. Through the rear wall isp laced a combustion chamber block 27 to the rear ofwhich is the oil burner 28. This oil burner has connected thereto an air pipe 29 and an oil pipe 30. The oil; pipe is provided with a regulating valve 31 by means of which the amount of oil delivered to the burner isregulated. Slidably mounted on the rear wall 14; is a i on damper or closure 32 by means of which the opening through the combustion chamber block may be closed. The regenerator is provided with an arch 33 on which rests a coil of oil pipe 3%, one end of this coil is connected to the oil pipe 80, and the other end to any suitable source of oil supply, not shown. The purpose of this coil is to turnish heated oil to the burner so that combustion can be more easily obtained. lithin the regenerator 23 is a coil one end of which is connected to the valve 36, the other end to the air pipe 29. This is tor the purpose of supplying highly heated air to the oil burner where it mixes with the oil prior to entering the combustion chamber.

Resting on top of the walls 20 and on shoulders 36* formed on the wall 16 are a plurality of blocks 37. These blocks forming the floor of the baking chamber These blocks may be provided with openlugs 89 so as to permit the ready passage of heat from the passage ways 21 and into the baking chamber. It will be noted from Figs. 3 and 5 that the blocks 37 do not extend completely to the front wall but are spaced apart therefrom so as to form passage ways d0. The purpose of these will be explained in detail later.

Resting on the blocks 37 are ware setting tiles 41, these tiles are for the purpose of supporting the racks on which the ware to be enameled and baked is placed. The baking chamber 38 is provided with an opening which is closed by means of a door constructed of a metallic shell 43. This nietallic shell has vertical extending ribs a l formed integral therewith. and the upper and lower edges of the casing 43 are provided with openings 45. Against the ribs ll is placed a piece of sheet metal This together with the openings i?) and ribs l i forms air passages 47 which run vertical and prevent the door casing from becoming too intensely heated. Placed against the sheet l6 is a filling of heat insulating material 4'7. When this material is in place. the door facing 48 is placed in position. This door "facing is constructed of refractory material as is all ot the brick work used in the furnace. I may however, it it is desired to cheapen the construction. use ordinary building brick for the outside layer of the furnace walls. Pivotally secured to the casing 43 by means of studs 49- are links These links have passing through their free ends rods 51. the ends of which have bearing in the door slides 52. These slides lit in channel shaped guides 53 which are placed on each side the door and at some distance in front of the wall 13. The guides are secured to the furnace by means ot' straps or other suitable securing means 54-. It will be noted from Fig. 11 that the slides 52 have openings 55 formed therethrough, into which openings, the ends of the rods 51 are inserted and in order to prevent any sai'tting oi. the links, a tube is placed between the links (see Fig. ilecurcd to the guides 53:3 is a slide stop 57, the purpose of which is to limit the downward movement of the door slides The purpose of this limiting or the movement will be explained in detail later.

The top of the door is preferably provided with integral ea s 58 to which are secured cables or links 52). These links come toget er and secured to a ring (it) which is in turn secured to any suitable hoisting means This hoisting means may be either an air hoist as illustrated, or may be a block anc tackle or any other suitable operating moans. An air or electric hoist hone. er is preferable because the doors for a furnace this type are eL-ttren'iely heavy, weighing in actual practice in excess of i000 lbs. The entire furnace is preferably placed on a concrete foundation On top of this foundation is placed a layer of insulating material (33, this is for the purpose of preventing the heat "from reaching the concrete which might cause its cracking. On top oi the arch 233 a layer oi insulating material (iii: which held in position by means of re tractor-y t les l vithin the regenerating chauib r 23 is a second air coil (56, one end w .ich connected to the valve the other end connected to the rear wall of the furnace. This rear wall is provided with 'ng (l? which is in alinen'ient with the pipe and is tor the purpoze of permitiii.

he air to enter the baking chamber 3% the gases therefrom. The

ts ot a housing 38, this housd with screw threaded nipples Secured in the nipple (it) is .70 T2. the other end 0t which This blower is (3 co ing is pro". (19. TO and one end oi A blower 73.

f providing the necessary red in the nipple '70 is 35. The nipple if]. has

amountoi the end Yet at the coil secured thereto one end of the coil (36. The housing (353 is provided with a flange "I5, to which flange the cover 755 is secured. liocatcd within the housing is a 1' TT, this di provided with a circular ope ing 78 which is designed to be brought in alineincut with the screw threaded nipple 1'1) and with an arcuate openinn' 'i'l) which is designed be brought in alinenient with the nipple lizitending through the cover TC id on which the disk is mounted. is held in close contact with the of the housing 38 by means of a p j in Secured to the shalt SO and 'oii oi the cover it; is cam 82 and a wheel 83. The wheel is for h p pose of turning the shaft which simu taneously rotates the disk 77 and cam 82. Contacting with the cam 82 is a roller S-lwhich is lib carried by the. lower end of a slidably mounted rod 85. The upper end of the rod 85 is connected to a rocker arm 86 which is pivotally mounted in a bracket 87. The opposite end of the rocker arm 86 is connected to a link 88, which link is in turn connected to a lever 89 carried by a valve 90. This valve iscarried by the oil pipe 30 and is for the purpose of cloigaing oil-l the pipe when it desired to stopthe firing. A spring Si is connected to the rocker arm 86 tor the purpose of holding the roller 8% in close con tact with the cam and for closing the valve 90 after the cam has been so rotated that the roller El i passes its highest point. The oil is designed to he l ed to the burner under pressure and as there are various devices on the market for this purpose, the same has not been shown nor has the burner been de-. scribed in detail for the reason that it is one of the many commercial types of burner now used.

The operation of my device as :tollows The oven door is first lowered into position so that the slides 52 contact with the stops 57. A continued lowering of the door now brings the links into action and permits the door toswing toward the "urnace wher its weight holds it securely against the front of the furnace and closes the opening. The blower 7 is then started. atter which the wheel 88 is rotated until the opening 78 is in alinement with the nipple 70. This permits the air to pass through the coil and into the burner, at tile -me timethe cam is so rotated the valve 90 is opened this permits the air and oil to reach the burner simultaneously and enter through the ignition chamber block, the slide e having been previously opened. It is of course, essential that the damper 26 be also opened at this time. The heat generated by the burner passes into the baking chamber 38 and thence downward into the passage ways 21 through the openings 39 and 40. The heat then passes rearward through the passages Ziand into the regenerator 23 and from ther it passes up through the chimney.

. In this way in a short time the coils and (S6 become heated and deliver hot air which materially assists the combustion. After the proper temperature has been reached in the baking chamber, the lower portion of the turnace is intensely hot also. The wheel 83 is then turned which removes th opening 78 from alinementwith the nipple and prevents anv further oassaue of air through the q/ L t 1 L coil 35. As soon as this closing off of air has been accomplished the roller 84 leaves the highestpoint of the cam 82 and the spring Slldraws the rocker-arm 86 into the position shown in 2 simultaneously closing ed the oilv The slide 32 is then lowered to prevent ingress of cold air and egress of heated air. A continued rotation of the hand-wheel brings the .arcuate slot in alinement with the nipple 71. this permits air from the blower to enter the coil 66 become heated and be delivered through the opening (37 into the interior of the furnace. This hot air completely fills the furnace and drives all of the foul gases in. the furnace before it and out through the chimney and being highly heated does not materially lower the temperature of the furnace, and by driving the foul gases out through the chimney there is no possibility 01: these gases escaping into the work room during the charging of the furnace and affecting the health of the worker. After the l' :nacehasbeen thus scavenged the hand wheel is turned suiiiciently far to bring the slot '4' 9 out of alinement with the nipple 71, both coils 35and G6 are now cut oil from the air supply and the damper 26 closed. This closes all openings to the furnace and prevents the admission of any additional air. The door is then raised so that the furnace can be charged. In raising the door the door will first move upward and away from the trout of the. furnace until it contacts with the uppermost rod (see Fig. 10 This prevents any further outward swinging ot the door. A continued raising movement now causes the slides 59. to move upward in the guides 53 thus clearing the opening 42 and permits the introduction of ware. .Fitterthis the door is again lowered, as previously described, and when in this posit-ion it will be impossible for the door to move outward and permitthe escape ofthe heat from the baking chamber. Additional heat is constantly supplied from beneath the floor of the furnace through theopenings 39 and .10 and as there is no outlet to the upper end of the baking chamber the heat is re tained therein much longer thanvis possible in furnaces where the baking chamber is connected to the chimney.

After the ware which has been introduced into the baking chamber has become heated to the desireddegree necessary for baking the enamel thereon which heating is accomplished by the radiation of the heat stored in the refractory masses of the sides, top and bottom and also in the passage ways 21 of the interior oi? the furnace, the ware is withdrawn and as this baking has lowered the temperatureol the furnace slightly the firing operationand scavenging isrepeated. The. only difference being that after the fun nace has been once heated, hot air is immediately supplied to the burner 28. i

The regulation of fuel and the air supply to the burner by means ol various valvesand the duration of firing time permits a positive heat control inside the furnace. The heat nameled, the lighter ware, such as k tchen 1-.tcnsils and the like requiring a higher degree of heat than the heavier ware, such as bathtubs and similar articles.

It is of course ecessary in the construction of my device to provide suitable openings for the introduction of pyrometers so that the heat within the baking chamber can be ascertained and regulated.

By the use of my device the scavenging of the furnace of foul gases is accomplished by a blast of highly heated fresh air. This not only makes the operation quicker but agreat deal surer than in the present type of enameling furnaces where the only scai-enging done is by the admission of air through the oven door. Furth rmore after the scavenging is lone and before the oven door is open, all communication with the chimney is closed olf thus preventing any ingress of cold air whereas in the previous type of furrace it was necessary in order to thoroughly scavenge the oven, to leave the dan Der open momentarily, this naturally resulted in a loss of temperature and it was n cessary to heat the oven considerably more than was re quired for the aking temperature so that the temperature of the furnace would be the proper degree after the scavenging was accomplished. This meant a longer firing perioo and resulted in the necessity of. using more oil as well as using additional time for the firing period. By the use of my device and method this firing period is materially red ced and due to the consequent saving in time, the output of the furnace increased.

Another inportant feature of my device is the construction of the floor In previous devices it was possible for ware which fell off of the racks to fall down into the lower part of the furnace. This in time no cumulated therein and necessitated the sh u"- ting down of the furnace for a considerable time while this ware was being removed. The ware sodropped is of course rendered. useless and must be scrapped whereas in my device any ware falling off of the racks can be readily drawn out through the door by means of a suitable tool and as this is done when removing the completed batch, this additional waste is eliminated.

By my construction a bottom or floor for the baking chamber is provided which has great mechanical strength so that the heaviest articles can be baked tierein and this bottom being supported by the solid partition walls furn'shes an additional mass for storing and disseminating heat directly underneath the ware which makes my device especially applicable for enameling extra heavy ware.

By the introduction of preheated air into the burner a great deal of the waste heat is saved and the temperature of the flame is sod because the gases issuing from the heady been highly heated belted. This is a distinct adhe use of cold or only slightly air being supplied to the burner. rthermore the preheating of the .oil or cl s pplied to the burner also increases .c ency of the flame due to the fact not necessary to waste a great eat units to bring the combusup to the igniting point and a higher temperature can be shorter time, which results in increases furnace cutout, the possibility arm l consequently cached in a quick changes from low to high temperature and the decrease of fuel consumption.

-frnother ure of my device is the location of the passage ways beneath the bakchamber, in so far as most of the heat is d awn (h vnward near the door. This to a great extent eliminates the cooling of the forward portion of the furnace when charging the major portion of the heat travels downward through the openings 40, so that the forward portion of the oven attains a greater heat and when the damper is closed, this heat and heat from the passage ways forms a cushion and prevents the entrance of cold outside air, which entrance of air has always been detrimental to heats in enameling furnaces wherein the scavenging was done through the door.

Furthermore in my devi e the heating of the rerraetory material has to be only slightly higher than the heat required for vitreous enameling which is far below the destructive heating for high class refractory material. This assures an almost indefinite life for the refractory materials and the con sequent absence of costly repairs and shutdowns.

Ti hile T have shown and described my device as utilizing an oil burner, I do not desire to limit myself thereto as either artificial or natural gases can be readily used for heating with only slight modifications in the burner and air supply. Such modifications however, putting it within the province of anyone skilled in the burner art.

Having fully described my invention What I claim is:

l. The method of enameling ware which consists in bringing an enameling furnace to the desired temperature, scavenging the products of combustion from said furnace through its chimney and without materially lowering the temperature of the furnace, and then inserting the ware to be enameled.

2. The method of enameling ware, which consists in bringing an enameling furnace to the desired temperature, scavenging the products of combustion from said furnace with preheated air, and then inserting the were to be enameled.

3. The method of enamelmg Ware which neaasso consists in bringing an enameling furnace to the desired temperature, scavenging the products of combu on from said furnace through its chimney with air under pressure and without mater ially lowering its temperature, and then inserting the ware to be enameled.

l. The method of enameling ware, which consists in bringing an enameling furnace to the desired temperature, scavenging the products of combustion from said furnace by preheated air under pressure, and then inserting the ware to be enameled.

The method of enameling ware, which i s in first bringing an enameling furnace to the desired tenuiierature, scavenging the products of combustion fr m. said fur nace through the chimnev while its charging and combustion chamber openings are closed without materially lowering its temperature, closing the chimney opening, and utilizing the heated air in the furnace to prevent the entrance of cold air while the ware to be enameled is being inserted.

6. The method of enameling ware, which consists in bringing an enameling furnace to the desired temperature, scavenging the products of combustion from said furnace with preheated air, and. then inserting the ware to be enameled, closing all openings in the furnace and utilizing the heated air in the furnace to prevent the entrance of cold air while the ware to be enameled is being inserted.

7. The method of enameling ware which consists in bringing an enameling furnace to the desired. temperature, closing the firing opening in said furnace, admitting air under pressure to said furnace for scavenging the products of combustion therefrom and without mate ially lowering its temperature, and driving said products of combustion out through the chimney, closing said air passage and chimney and utilizing the heated air in the furnace to prevent the entrance of cold air in the furnace while the ware to be enameled is inserted.

8. 'ihe method of enameling ware, which consists in bringing an enameling furnace to the desired temperature, scavenging the products of combustion from said furnace by preheated air under pressure, and then in sertinp; the ware to be enameled, closing all openings in the furnace and utilizing the heated air in the furnace to prevent the entrance of cold air while the ware to be enameled is being inserted.

'9. In an enameling furnace, a furnace having heating and scavenging means, a door adapted to move to and from said furnace and seat itself tightly against the front of the furnace by its own weight when in lowered position, and means for raising said door in and out of closed position.

10. An enameling apparatus comprising out, a rear and two side walls, a baking located within said side walls, a said baking chamber, passage ways beneath said. floor and communicat said baking chan'iber, a regenerater in communication with said rys, air coils located in said rechamber, a valve for controlling at sion of air to said coils, and means pro ecting heating medium into said hug hamber,

11.. ran cnameling apparatus comprising a. l? l era sing; chamber having a charging openand a. floor, passage ways located beneath d floor, said passage ways having comm nication with the baking}; chamber adjacent the charging opening, means for pro- I cting a heating medium into the baking chamber, means for scavenging the products combustion from said apparatus, and a single valve for controlling the heating and scavenging means.

12. The enameling apparatus of. claim 11 in which the floor of the baking chamber is reticulated.

13. An enameling apparatus comprising a baking chamber having a charging opening and a floor, passage ways located beneath said floor, said passage ways having communication with the baking chamber adjacent the charging opening, a closure for said charging opening means for projecting a heating medium into the baking chamber, means for scavenging said baking chamber of the products of combustion, a regenerating chamber in communication with the passage ways, aplurality of air coils located within said regenerating chamber, said coils adapted to deliver heated air to the heating and scavenging means, and a single valve for controlling the admission of air to said coils in sequence.

14:. In an enameling apparatus, a baking chamber having a floor, a regenerating chamber, and passage ways connecting said regenerating chamber and baking chamber, said passage ways located beneath the baking chamber, a fuel burner means for supplying a preheated fuel to said burner, means for supplying preheated air to said burner, means for scavenging the baking chamber, air coils located within the regenerating chamber, said coils having communication with the fuel burner and scavenging means, and a single valve for admitting and closing off air to said coils. said valve adapted to close off the supply of fuel simultaneous with the closing off of air to the burner.

15. The method of enamelin ware which consists in producing combustion in the baking chamber of an enameling furnace, scavenging the products of combustion therefrom without exposing the baking chamber to astmospheric temperature, and iastly'inserting the Ware in said baking chamber.

16, The method of enameiing ware which consists in prod icing combustion in he bakin chamber of an enameiing furnace drawx the products of combustion downward beneth the vfloor of the baking chamber Zil'li pern ting the same to pass out through a 10 chinmey discontinuing said combustion by air under pressur forcing the products of combustion from the ba ing chamber and through the chimney, ciosing said chimney, opening the baking chambe and inserting 15 the ware therein, and then closing the baking chamber.

17. The method of enameiing ware which consists in producing combustion in the baking chamber of an cnan'ieiing furnace, dis- 20 continuing said combustion, closing the combustion opening in tie baking chamber,

forcingthe products of combustion from said baking chamber and out through the chimney Wit-h preheated air, closing said chimney after the products of coniibustion have passed therethrougrh, opening sai-i chamber and inserting the ware therein. and then closing said chamber whiie the ware is being: baked.

18. In an enameling furnace, a furnace having a heating and scmenging means, a charging opening, a door adapted ;o be raised and lowered located before said opeing, means for raising; and iowering ii door, and means carried by the door whereby the same is moved toward the furnace and seated tightly there-against by its own weight when the door is in lowered position, whereby said door is prevented from being forced away from the front of the charging opening by the expansion of air within the furnace.

In testimony whereof, 1 have signed my name to this specification. 

